Trix of said serrell



UNITED STATES PATENT OFFICE.

JAMES E. SERRELL, OF NEW YORK, N.` Y.; MARY J. THOMSON ADMINISTRA- TRIX OF SAID SERRELL, DECEASED.

DERR'ICK.

'SPECIFICATION forming part of Letters Patent No. 487,453,dated December 6, 1892.

v Application tiled March 4,1892. Serial No. 423,713. (No model.)

To all whom it may concern.' l

Be it known that I, JAMES E. SEERELL, a citizen of the United States, residing at the city and State of .New York, have invented van Improvement in Derricks, of which the following is a specification.

In Letters Patent No. 142,740, granted to me September 9, 1873, a derrick is represented in which the weight that is acted upon is xo suspended from a counterpoised boom, so that tral support as the weight that is being raised increases. Hence there is onlya verti cal pressure upon the mast or frame supporting the I5 counterpoise-boom. In this construction dif- I culty arose in the winding of the hoisting rope or chain around the mast when the sus'- pended weight and boom were revolved.

The present invention is made for allowing zo the weight that is suspended and the counterweight and the boom to be revolved with freedom around the mast or supporting-frame without the hoisting rope or chain fouling with such mast or support, and I also provide a peculiar counterpoise-platform that is capable of being loaded to a greater or less eX- tent, according to the weight to be raised.

In the drawings, Figure l is an elevation with the cap in section, and Fig.y 2 is a plan 3o View.

The mast is composed of three, four, or more spars or frames, as represented at A, and these are to be of Asuitable size, according to the strength required in the derrick, and they 3 5 are connected at their lower ends with a base or support B, and at the upper ends is a cylindrical cap O, havinga central opening, and this cylindrical cap C is permanently connected to the frame A in any suitable man- 4o ner, and such cylindrical cap forms a base to the turn-table D, such turn-table having a cylindrical flange surrounding the cap C, and the parts may be provided with rollers orballs to lessen friction, if desired.

Upon the turn-table D are the two sheaves E and F, supported in suitable jaws, and the inner edge of the sheave E is in line with the vertical center of the turn-table D, or nearly so, in order that the flexible hoist-such as a 5o rope or chain G, which passes up centrally i through the cap C and turn-table D-may around any portion of the mast orframe when 6o `the boom is being rotated. the counterpoise swings away from the cen- The boom H is of any desired size and character. Usually it is composed of two side pieces or spars joined together at their ends, and these spars are sufficiently distant from leach other for the mast or frame to be between them Without coming into contact, as

illustrated in Fig. 2, and the boom is suspended by connections-such as the rods or .chains K IKL-extending from the respective 7o ends of the boom to the turn-table D, where theA ends of the rods or chains K K are permanently connected by eyes or loops, so that the entire boomis free to swing upon the eyes or loops at 3, and in consequence of the rods 7 5 K K being at downward inclinations from such eyes or loops 3 the end of the boom which may swing downwardly moves toward the mast and the end of the boom that swings upwardly moves farther away from the mast, 8o the same as in the aforesaid patent, and by these movements the weight L that istoabe lifted and the counterpoise O come to lan equilibrium, and there is only a downward pressure upon the mast or frame by the Weights that are carried.

The counterpoise O is composed of a-platform 4 with a rim 5, so as to be adapted to receive stone or other easily-procured substances, so that the platform may be loaded in proportion to the weight that is to be raised, and by making this platform with the side extensions 6, that pass at opposite sides of the frame or mast, I am enabled to load the platform heavily and to bring the weight 0f 95 the counterpoise into operation advantageously, as hereinafter described, and by projecting the platform at 7 the outer ends thereof maybeloaded so as to act with leverage upon the hoisting appliances next described.

The chains Pserve to suspend the counter- IOO poise, as in my aforesaid patent. They are connected at their upper ends by loops or eyes S to the turn-table D, and at their lower ends to the side extensions 6 of the platform, and thehoisting-block Q is connected by three or four branch chains Q to the platform 4, so that the platform will be raised gradually by the block and tackle Q. The hoisting rope orchaiu G passes, preferably, through a sheave S and vertically, or nearly so, over the sheave E, through the blocks T and U, and returns through the block T and over the sheave F, thence through the blocks V and Q, and the end of the rope G is attached at l0 to the boom H. It will be observed that the block U is single, and the blocks T, V, and Q are double, so that there will be the necessary purchase in raising the counterpoise O; but the blocks may be lnade with a greater number of sheaves, so as to increase the purchase, if desired, and I provide a guy rope or chain W over a sheave 12, by which the weight after it has been raised can be drawn inwardly toward the mast or allowed to swing out, as desired, and this sheave or block 12 is connected with the tu rn-table, so as to move with the boom as the same may be revolved. It will now be observed that when the block U is connected to the weight L to be raised and the chain G is drawn upon by any suitable' power such weight is not raised until the rope or chain G has been drawn upon sufficiently to act upon the counterpoise O and lift the same off the deck or platform supporting the derrick, and in lifting the counterpoise a large portion of the weight is at first unacted upon, because it hangs by the chains P, and as the counterpoise is lifted it swings outwardly from the mast, more or less, according to whether the weight is entirely taken by the blocks V Q and the boom or partially by the suspendingchains P, and the hoisting operation is continued until the counterpoise is sucient to raise the weight and the counterpoise has a greater leverage, as the other end of the boom may be pulled down toward the weight and the counterpoise end of the boom thrown farther away from the mast, and after the counterpoise is sufiicient to raise the weight the weight and the counterpoise hang at the re spective ends of the boom and the weight can be drawn up more or less by the action ofthe chain or rope G without disturbing the equilibrium of the parts, and when the weight has been raised to the desired height the boom may be swung around more or less, 0r the weight may be drawn into the platform or deck upon which the derrick is placed; and it will be observed that under all circumstances the boom, with the counterpoise, swings according to the weight to be raised or the leverage of the weight upon the boom, and as the weight is lowered the counterpoise will also be lowered, and by the action of the chains P it will be swung in until it is suspended at one end by such chains and the other end is lowered gradually and rests upon the deck or platform of the derrick. In consequence of the divergence of the chains below the block the two parts of such chain that pass toward the suspendingchains P may become slack as the counterpoise-platform is lowered into the inclined position of rest, and such chains when drawn upon lift the platform and hold it level, or nearly so, when brought into action as a counterpoise.

Whenever the dei-rick is to be used upon a weight that is beyond a vertical line below the moving end of the boom, such weight may be drawn toward the boom before being lifted by a bridle-pulley at the base of the mast, as shown in my aforesaid patent. By these irnprovements the action of the counterpoise is rendered more reliable and the entire derrick can be more easily manipulated than in my former patent.

I claim as my invention- A l. The combination, with a stationary supporting mast or frame, of a turn-table at the upper end of such mast or frame, such turntable having a central or nearly central opening, a boom composed of two pieces passing the mast freely at opposite sides and united at their ends, and devices for suspending the same from the turn-table, a counterpoise suspended at one end of the boom, a sheave upon the turn-table, and a exible hoist passing through the turn-table over the sheave to the hoist-block, substantially as set forth.

2. The combination, in a derrick, of a stationary supporting mast or frame, a turn-table upon the upper end thereof with a central opening, a boom composed of two pieces boom, a sheave upon the turntable, a flexible hoist, a block at the lower part of the mast or frame through which the hoist passes and extends up through the turn-table and over the sheave thereon, a hoist-block at one end of the boom, and another to be counected with the weight and through which the Iiexible hoist passes, substantially as set forth.

3. The combination, in a derrick, of a stationary mast or frame, a turn-table upon the upper end thereof, two sheaves supported by the turn-table, a boom composed of two pieces passing the mast freely at opposite sides and united at their ends and devices by which it is suspended from the turntable, a counterpoise, and the blocks at the respective ends of the boom, and the flexible hoist passing through the turn-table over one of the sheaves to the blocks of the weight to be raised and returning over the other sheave to the blocks of the counterpoise, whereby the power is iirst exerted to raise the counterpoise until it has sufficient leverage for lifting the weight, substantially as sety forth.

4. In a derrick, the combination, with the stationary mast or frame, the turn-table at the top thereof, and the boom composed of IOO IIO

sides and united at their ends and devices for suspending the same from the turn-table, a counterpoise, and hoisting mechanism, the iiexible hoist passing through the middle of the turn-table at the top of the mast, so that the turn-table and boom can be revolved, substantially as set forth.

Signed by me this 2d day of March, 1892.

JAMES E. SERRELL.

Witnesses:

GEO. T. PINCKNEY, WILLiAM G. Morir. 

